Monitoring physiological functions could someday be as easy as slipping on a T-shirt, thanks to a new method for making smart fabrics. By coating common cotton thread with carbon nanotubes, researchers have developed a simple and inexpensive route to electronic textiles (Nano Lett., DOI: 10.1021/nl801495p). The team, led by Nicholas A. Kotov of the University of Michigan, Ann Arbor, and Chuanlai Xu of China's Jiangnan University, prepared the intelligent yarn by dipping threads in a polyelectrolyte solution containing carbon nanotubes and then letting them dry. The technique could easily be integrated into existing fabric processing, the authors note. The nanotube coating makes the threads conductive enough to allow a battery connected to the threads to power a light-emitting diode. And when the team used the protein-stabilizing electrolyte poly(sodium 4-styrene sulfonate) and added the antibody for human serum albumin to the solution, a change in the coated threads' conductivity indicated the presence of the key blood protein albumin. A garment made with these threads could have military applications, such as detecting how badly a person has been injured in a blast.